In all honesty, they could have gone a completely different route with this expansion. The whole idea of introducing the Pandaren was "meh" to me at first. I've warmed up to their storyline now, but I still dislike several aspects.
For one, the pet battle system... I think it's kind of retarded and doesn't belong in WoW whatsoever. I never liked collecting pets, and only did so in order to get achievements. I have no desire at all to have Pokemon battles while the whole of Azeroth is being destroyed by demons, old gods, etc.
Secondly, the extreme revamp of the talents. I'm on the fence about this one. I like how legitimately there are 2 or 3 viable options instead of just "one dps, one pvp spec", but then again I'm tired of them completely changing things up on us every single expansion.
Third, I feel like all the raids are just sort of anti-climatic.

Alas, until Sargeras shows up, my favorite expansion will still go to Wrath of the Lich King, by far.

Edit: Not really into PVP, but from what I hear... it's kind of broken. =X

Just don't try to do every daily, every day and you will be fine. Don't let that scare you away. The raiding is some of the best since BC. PvP still sucks, but it's WoW... so yeah... Leveling is fun, still pretty linear, but not as bad as Cata.

Pet battles are a neat idea, but not all that great. better to just grab a gameboy and play Pokemon. Scenarios are meh, but a decent little distraction.

The continent looks great.

Overall I would say It's the best expansion WoW has had. Just as good as if not better than BC for me.

It would be excellent but for the shitty time to reward ratio and emphasis on daily questing bullshit. Of course your gonna hear their optional and they totally are. About as optional as running heroic dungeons was in Cata. They are optional if you want to go nowhere in the game.

Leveling: Just awful and grueling, especially if you've done every other expansion when it was relevant. I actually liked leveling until Pandaria hit.

Stuff to do: As a PvE player, enjoy doing dailies, dailies, and more dailies after hitting 90. As a PvP player, enjoy one-shot stuff killing you, or being unable to kill stuff because of healers.

Raiding Content: Some of the best content since early Lich King and BC. Cataclysm was just awful and late LK got repetitive.

Pet Battles: Makes you wish you were playing Pokemon.

Scenarios: Great concept, HORRIBLY executed.

LFR: Better known as "pray to your deity to get loot you can actually use". (Done LFR every week. Got about 15 pieces total. Not a single one has EVER been equipped because I had better stuff on -_-)

Conclusion: Eh. If you plan to raid, it's really good content when you're raiding. For the casual player, it really isn't that great. Also if you're a Mage, DEFINITELY DO NOT BOTHER until we at least see 5.2. Mage QoL has never been worse, especially with the L90 talents.

I've been playing World of Warcraft now for 8 years, so perhaps my view is biased based on the fact that I am getting bored, but Pandaria offers nothing majorly different then any other expansion has. Everything looks nicer, and is smoother and some aspects are a lot of fun, but generally it is the same stuff again.

My only issues with MoP are that they gave the players more to do, but with less choice in how to do it, and when completed there really is no sense of accomplishment. Also I think I have dealt with more bugs making it to live in MoP than with any of the other xpacs I played previously (BC & Cata)

I hope that was as ambiguous as your question.
Instead of asking for other people's opinions... how about you play the trial and form your own? What do you have to lose aside from leaving your PC on overnight to download it? o.O

Leveling is good, the zones are good, dungeons are good, raiding is good, lots of stuff to do.

The only thing I ever hear complaints about is pvp balance, which matters not at all to me as a person who pvps regularly but at level Suck™, and about dailies which are admittedly plentiful but are not mandatory.

I dislike dailies, so my approach to the abundance of them was to not treat it like a huge, required job and just not do them if I don't feel like. It has staved off the burn out so many people are upset about. I got my gear directly from raiding instead, and while I do try to get my 90 lesser charms a week for my loot tokens, that's only, like, one day of aggressive dailies or a few days a week of a moderate amount, which is not really a big deal. In practice, I'm probably doing less dailies this expansion than I've ever done since their introduction.

With pleasure! *does the little french hand/mouth pop at the sommelier* Chop chop Louis!

LOL. I like you

Anyways, if you are like TonyIommi and want to get every reward in the game by chain-running heroics for a week, you won't like Pandaria.
If you like raiding but can't stand having to stoop to other activities like "questing" to progress your character, you might not like Pandaria.
If you're hardcore PvP, you might not like it either.

If you like doing a variety of game activities, you might like Pandaria. The story is great, and the different ways to progress in game are a good new addition.

Having a continent again makes the game feel like an expansion again. Blizzard did a good job with the culture and theme. As for things to do, there is a lot, but like most things in an MMO, it's optional. But if you want to do everything the game has to offer, there is a ton of stuff.